In The Godfather, there is an important scene in an Italian Restaurant with dialogue between Michael Corleone and Virgil Sollozzo. There is dialogue spoken in Sicilian (according to the script) that does not have English subtitles.
SOLLOZZO now begins in rapid Sicilian. MICHAEL listening carefully and nodding every so often. Then MICHAEL answers in Sicilian, and SOLLOZZO goes on. The WAITER occasionally brings food; and they hesitate while he is there; then go on. Then MICHAEL, having difficulty expressing himself in Italian, accidentally lapses into English.
The Godfather is an American film and the dialogue is in English with the exception of this dialogue between Sollozzo and Michael. (Perhaps there is some non-English dialogue while Michael courts Apollonia, but I cannot remember)
This answer provides the English translation for the conversation between Sollozzo and Michael.
My question is, Why wasn't there English subtitles provided for this scene? The film is an American film with English dialogue. This scene appeared to be an important plot to the film. Is there an explanation from filmmakers on why there were no English subtitles provided for this particular scene?